A low noise current buffer circuit includes a first transistor, for receiving an input current, a second transistor, for draining a first current from a drain of the second transistor according to the input current received by the first transistor, a third transistor, for outputting first current, a fourth transistor, for outputting a second current to an output resistor, to generate an output voltage, and a feedback capacitor, for eliminating impacts of noise of a system voltage on the output voltage.